Dehydration of >3 % body mass impairs endurance performance irrespective of the individual's knowledge of their hydration status, but whether knowledge of hydration status influences performance at lower levels of dehydration is unknown. This study examined whether perception of hydration status influenced endurance performance. After familiarisation, nine active males (age 25 ± 2 y, V̇O_2peak 52.5 ± 9.1 mL kg min⁻¹) completed two randomised trials at 34 °C. Trials involved an intermittent exercise preload (8 × 10 min cycling/5 min rest), followed by a 15 min all-out cycling performance test. During the preload in both trials, water was ingested orally every 10 min (0.3 mL kg body mass⁻¹), with additional water infused into the stomach via gastric feeding tube to produce dehydration of ∼1.5 % body mass pre-performance test. Participants were told intra-gastric infusion was manipulated to produce euhydration (0 % dehydration; Perceived-EUH) or dehydration (2 % dehydration; Perceived-DEH) pre-performance test, which was told to them pre-preload and confirmed after body mass measurement pre-performance test. Body mass loss during the preload (Perceived-EUH 1.6 ± 0.2 %, Perceived-DEH 1.7 ± 0.2 %; P = 0.459), heart rate, gastrointestinal temperature and RPE (P ≥ 0.110) were not different between trials. Thirst was greater at the end of the preload and performance test in Perceived-DEH (P ≤ 0.040). Work completed during the performance test was 5.6 ± 6.1 % lower in Perceived-DEH (187.4 ± 37.0 kJ vs. 176.9 ± 36.0 kJ; P = 0.038). These results suggest that at lower levels of dehydration (<2 % body mass), an individual's perception of their hydration status could impair their performance, as well as their thirst perception.

无论个体是否了解自己的水合状态，>3%体重的脱水都会损害耐力表现，但了解水合状态是否会影响较低脱水水平下的表现尚不清楚。这项研究检验了对水合状态的感知是否会影响耐力表现。熟悉后，九名活跃男性（年龄 25 ± 2 岁，V̇O _2peak 52.5 ± 9.1 mL kg min ⁻¹）在 34 °C 下完成了两项随机试验。试验包括间歇性运动预负荷（8 × 10 分钟骑行/5 分钟休息），然后进行 15 分钟全力骑行性能测试。在两项试验的预负荷期间，每 10 分钟口服一次水（0.3 mL kg 体重^-1），并通过胃饲管将额外的水注入胃中，以在性能测试前产生约 1.5% 体重的脱水。参与者被告知操​​纵胃内输注以产生水合状态（0％脱水；感知-EUH）或脱水（2％脱水；感知-DEH）预表现测试，在预负荷前告知他们并在体重后确认测量预性能测试。预负荷期间的体重损失（感知-EUH 1.6 ± 0.2 %，感知-DEH 1.7 ± 0.2 %；P  = 0.459）、心率、胃肠道温度和 RPE（P  ≥ 0.110）在试验之间没有差异。在 Perceived-DEH 中预载和性能测试结束时口渴感更大（P  ≤ 0.040）。在 Perceived-DEH 中，性能测试期间完成的功降低了 5.6 ± 6.1 %（187.4 ± 37.0 kJ vs. 176.9 ± 36.0 kJ；P  =  0.038）。这些结果表明，在较低程度的脱水（<2%体重）下，个体对其水合状态的感知可能会损害其表现以及口渴感知。